The Niners have since beaten the Seahawks, yet Brooks’ comment is relevant beyond that matchup.

The Niners have to prove they have the firepower to return to the Super Bowl. Eight of their players were named to the Pro Bowl on Friday; they must prove they are the NFL’s best team instead of simply a team with the NFL’s best players.

Additionally, the 49ers must prove they can beat the NFC’s best teams. This season, they’ve lost to the Seahawks, Panthers and Saints, plus the AFC’s Colts. Beating the Seahawks was a step toward silencing those who maintain the argument that the Niners can’t beat the best teams. Yet, they have still beaten only two teams above .500 this year, the Seahawks and Cardinals.

Individual players on the 49ers have something to prove as well. Colin Kaepernick has faced doubters for the majority of the season; he can quiet them with another deep playoff run.

Aldon Smith must prove that he can overcome his substance abuse and that his total of 19.5 sacks in 2012 wasn’t a fluke; a resurgence in the playoffs would help silence his doubters.

Even Michael Crabtree, who missed most of the season, must prove he is an elite wide receiver. If he can step up, lead the 49ers’ receiving corps and prove to be a reliable target for Kaepernick, he’ll join the ranks of the NFL’s best, despite lacking the statistical pedigree.

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Going back to team success, the 49ers clinched a playoff berth with their win over the Atlanta Falcons in Week 16. But an additional win in their matchup against the red-hot Arizona Cardinals in Week 17 would give them huge momentum going into the playoffs, so they can’t afford to take the week off.

As history has shown, momentum is important. With a few exceptions, Super Bowl-winning teams in the past several years have gone into the playoffs on hot streaks.

The 2012 Ravens are one of those exceptions, but the 49ers, who nearly beat them in the Super Bowl, won three of their last four regular-season games. So did the the 2011 Giants, and their Super Bowl counterpart the Patriots, won their final eight games of the regular season. The 2011 Super Bowl-champion Green Bay Packers won their last two regular season games, and the 2009 title-winning Pittsburgh Steelers won six of their final seven games.

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I could go on, but you get the point. Winning the Super Bowl can be done without late regular-season success, but it’s that much easier if a team goes into the playoffs with confidence and conviction. That’s why Week 17 is important, despite the 49ers’ playoff berth already being a lock.

The 49ers-Cardinals matchup is also important because the Niners aren’t out of the running for a first-round bye just yet. A San Francisco win and a Seattle loss would give the Niners the NFC West’s top spot; nothing could be more confidence-boosting than snatching the division title out of a rival’s hands on the final day of the season. Additionally, the advantage of facing the Seahawks at Candlestick, as opposed to CenturyLink Field, cannot be overstated.

However, if the 49ers are to show that they will take Brooks’ comment seriously and actually make a Super Bowl run, they have several facets of their game to improve. Improved clock management is one example, as Brian Burke of Deadspin notes. Putting away trailing opponents is another, as they showed in Monday’s narrow victory over the Falcons.

But that’s mostly nitpicking. The 49ers are in the midst of their second five-game winning streak of the season, and they’re firing on all cylinders. If they have a “we have something to prove mentality,” they should be just fine.